Highly Active Sb₂S₃-Attached Mo–WO₃ Composite Film for Enhanced Photoelectrocatalytic Water Splitting at Extremely Low Input Light Energy

Abstract

We prepared platelike Mo-doped WO3 films (Mo–WO3) deposited with Sb2S3 for photoelectrocatalytic (PEC) water splitting under visible-light illumination at extremely low input energy (1 mW cm–2). The 5% Mo–WO3 film exhibited optimal PEC water-splitting performance. Furthermore, Sb2S3/5% Mo–WO3 composite film achieved the highest photocurrent density of 0.42 mA cm–2, nearly 20 times as high as that of 5% Mo–WO3 film. The outstanding PEC water-splitting performance was mainly attributed to synergistic effects of Mo doping and deposited Sb2S3; that is, the enhanced PEC performance not only was assigned to the broadened optical spectrum but also improved electron–hole pairs separation and transfer efficiency. Density functional theory calculation revealed that Mo dopant can modulate the intrinsic electronic structure of WO3 and introduce impurity energy levels resulting from the hybridization between M 3d and O 2p states around the Fermi level, resulting in improved electrical conductivity. Therefore, this work offers new insight for designing metal elements doping into WO3 associated with multifunctional electrode materials for high PEC visible-light-induced water-splitting activity in neutral electrolyte.

Enhanced Photoelectrochemical Water Oxidation with Ferrihydrite Decorated WO3

“…With the deposition of Fh, the Fh/WO 3 achieves a maximum photocurrent density of 0.61 mA/cm 2 at 1.23 V (vs. RHE) when the deposition time is 30 min, which is 1.79 times higher than the WO 3 (0.34 mA/cm 2 ). The PEC performance of the obtained Fh/WO 3 is comparable to the previous reports of WO 3 based composites [33,34]. The transient photocurrent density versus time (I-T) curves of corresponding photoanodes were measured at 1.6 V (vs. RHE) and the results are presented in Fig.…”

Two‐Dimentional Nanostructured Metal Oxide/Sulfide–Based Photoanode for Photoelectrochemical Water Splitting

“…Among various strategies, element doping is one of the most efficient strategies to accelerate the carrier dynamics of 2D metal oxide/sulfide photoanodes. [ 97 ] Moreover, element doping could also introduce new band states and thus adjust the energy band structure of semiconductors. [ 48 ] Thus, the light absorbance ability and redox ability of these photoanodes would be improved.…”

“…In addition, researchers have constructed other type II heterojunctions for PEC water splitting as well, such as WO 3 /CdIn 2 S 4 , [ 45 ] CdS/CdIn 2 S 4 , [ 115 ] and Sb 2 S 3 /Mo‐WO 3 . [ 97 ] According to the previous discussions, constructing type II heterojunctions with small‐bandgap semiconductors can improve the light absorbance, carrier separation, and transfer of photoanodes simultaneously.…”

Ultrafine MoS2/Sb2S3 Nanorod Type‐II Heterojunction for Hydrogen Production under Simulated Sunlight

“…[9] However, Sb 2 S 3 easily grows into large-size structure in synthetic process, so that body-to-surface carriers' migration takes longer, which dramatically hinders its application in photocatalysis field. To address this critical issue, Cao et al supported Ag NPs on hollow Sb 2 S 3 microspheres to construct metal-semiconductor nanostructures, [10] Zhang et al constructed a WO 3 /Sb 2 S 3 heterojunction, [11] Du et al deposited Sb 2 S 3 on Mo-doped WO 3 films, [12] and Wang et al synthesized a Sb 2 S 3 /g-C 3 N 4 heterostructure. [13] Obviously, the formation of built-in electric field can effectively promote the photocarriers' migration in body structure, achieving highly improved photoactivity.Differently from Sb 2 S 3 , molybdenum disulfide (MoS 2 ), a typical 2D layered TMS semiconductor, is widely used to prepare photocatalysts with high-performance by serving as main catalyst or cocatalyst due to its excellent light-harvesting, easy body-to-surface photocarriers' migration, and abundant Transition metal sulfides (TMSs) have been widely used as photocatalytic materials in view of the merits of broadband light harvesting and low work function.…”